PBKey Fallback

When using PBKey Fallback, if an address match is not made to Master Location Data, but a match is made to a different dataset, the pbKey of the nearest MLD point located within the search distance is returned. To distinguish when a fallback pbKey is returned, the PBKey return value contains a leading character of "X" rather than "P", for example: X00001XSF1IF. Note, all of the other fields returned for the address match, including the geocode and all associated data returns, reflect the match results for the input address. The fallback pbKey can then be used for the lookup to the GeoEnrichment dataset(s), and the attribute data for the fallback location is returned for the match.

The relevance and accuracy of the returned attribute data using a PBKey Fallback location is highly dependent on the type of GeoEnrichment data, as well as the PBKey Fallback search distance. PBKey Fallback is intended for use with GeoEnrichment datasets that have polygonal-based data, rather than point-specific data. For example, the PBKey Fallback option may be suitable for determining the FEMA flood zone for a given location using the Flood Risk Pro GeoEnrichment dataset since it contains data that represents a polygonal region rather than a single coordinate. However, it is important to note that the accuracy of the returned data would very much depend on the size and nature of the individual polygonal features described in the GeoEnrichment data, combined with the search distance used to locate the nearest Master Location Data point. The search distance is configurable with an allowable search radius of 0-5280 feet and a default value of 150 feet.

The PBKey Fallback option is available in GeocodeUSAddress and ReverseGeocodeUSLocation. For more information, see FIND_APPROXIMATE_PBKEY in Geocoding Options for GeocodeUSAddress and Configuration Options for ReverseGeocodeUSLocation.